Media streaming has become popular on handheld devices. Power saving is a key feature on handheld devices. For lower data rate streaming such as voice and audio the IEEE 802.11 has provided a well-known, fairly effective power saving feature. Typically, in IEEE 802.11, the power saving feature employs beacon frames, which wake up mobile stations during a sleep mode. Beacon frames control the wakeup period for a given mobile station, as the mobile station wakes up during transmission and goes to sleep when there is no transmission. Typically, the mobile station determines the beacon interval from the beacon frame. A beacon interval is the amount of time between beacon frame transmissions, and is typically fixed (e.g., fixed at 100 ms).
Unfortunately, the beacon interval can create unwanted buffer overhead and delay for higher rate streaming such as video. For example, if the beacon interval is 100 ms and if the data packets carry voice-grade data (e.g., 64 Kbits at 6.4 Kbits/sec), the buffering is not a problem. For higher data rate streaming, such as MPEG2/1-1.264 video streaming, the power saving method requires a larger buffer. For example, if the beacon interval is 100 ms and if the data packets carry video-grade data (e.g., 20 Mbits/sec at 2 Mbits/sec), buffering would be a problem if the buffer were not sufficiently larger. In a beacon interval, the buffer would accumulate video data at 2 Mbit/sec. As such, the access point would need at least a 2 Mbit buffer in order to achieve some power savings. However, the larger buffer requirement is expensive to make and requires more space.
Accordingly, what is needed is an improved method and system for data packet transmission. The present invention addresses such a need.